Faced with rising fax costs, a firm issued the guideline that transmissions of 10 pages or more must be sent by 2-day mail instead. Exceptions are allowed, but they want average to be 10 or below. The firm examined 35 randomly selected fax transmissions during next year, yielding a sample mean of 14.44 with the standard deviation of 4.45 pages.
At the .01 level of significance, is the true mean greater than 10?
2. An auditor reviewed 25 oral surgery insurance claims from the specific surgical office, determining that mean out-of-pocket patient billing above the reimbursed amount was $275.66 with the standard deviation of $78.11. State your hypotheses and decision rule.
At the 5 percent level of significance, does this sample prove the violation of guideline that the average patient should pay no more than $250 out-of-pocket?
(a) To test: H0: μ ≤ $250 versus H1: μ > $250.
(b) find out the t value.
(c) The null hypothesis must be rejected.
Is this a close decision?